Food companies face a critical question every time they develop a new product: will consumers actually like it? Creating a technically sound product means nothing if it fails to win over the people who matter most-the consumers. This is where affective tests become invaluable. These consumer-focused sensory evaluation methods measure subjective responses like preferences, acceptance, and overall liking, providing crucial data that can make or break a product’s success in the marketplace.
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What are affective tests?
Affective tests are sensory evaluation methods designed to measure the emotional and subjective responses of consumers toward food products. Unlike analytical tests that use trained panelists to objectively identify specific sensory attributes, affective tests utilize untrained consumers to gather data reflecting general market reactions. These tests focus on the fundamental question: Do people like this product, and would they buy it?
The distinction between analytical and affective methods is important to understand. Analytical tests are generally product-focused, providing objective data about sensory properties through trained assessors. Affective tests, on the other hand, are consumer-focused-they measure acceptability and preference rather than describing what a product tastes like. Both approaches serve different purposes in product development, but affective testing provides the crucial link between laboratory development and marketplace success.
Types of affective tests
Food scientists typically employ several categories of affective tests, each serving specific purposes in consumer research. The main types include preference tests and acceptance tests, both of which provide valuable but distinct information about consumer attitudes toward products.
Preference tests
Preference tests are comparative evaluations where consumers indicate which product they prefer when presented with two or more samples. These tests answer the fundamental question: “Which product do consumers like more?”
The paired preference test is the simplest form, where consumers choose between two products to indicate which one they prefer. This straightforward method provides clear data on consumer preferences between competing products or formulations. It works well when you need a direct comparison between a current product and a reformulated version.
The ranking test asks consumers to arrange multiple samples in order of preference, from most to least preferred. In a ranking test, the consumer ranks the product according to his or her preferences. This method efficiently compares several products simultaneously, making it useful when evaluating multiple prototypes or competitor products. However, ranking provides limited information about the degree of preference-you know the order but not how much more one product is liked over another.
Acceptance tests
Acceptance tests measure the degree to which consumers like a product, typically using rating scales. Rather than simply comparing products, these tests quantify how much consumers enjoy each product individually. This provides more nuanced data about consumer satisfaction levels.
The most widely used acceptance test method is the hedonic scale, which allows consumers to express their level of enjoyment or preference for a product. The hedonic scoring approach determines the scale of preference among products or the degree of pleasure and liking the product gives.
The 9-point hedonic scale
The 9-point hedonic scale is the most widely used scale for consumer acceptance testing in the food industry. This tool measures the degree of pleasure or liking of a product, with categories ranging from “dislike extremely” (1) to “like extremely” (9), with “neither like nor dislike” as the neutral midpoint.
The scale has an interesting history. It was created by Peryam and Pilgrim in the 1950s, initially to measure food preferences among soldiers in the U.S. Armed Forces. The military needed to understand what foods soldiers would actually eat, and traditional methods of gathering feedback were too subjective. The developers applied graphic rating scale principles from experimental psychology to measure the hedonic value of foods.
Since then, the 9-point hedonic scale has been used extensively with a wide variety of products and continues to be employed with considerable success. Its popularity stems from several key advantages. The scale is easily understood by consumers with minimal instruction. Results have proven remarkably stable, and product differences in liking are reproducible with different groups of subjects.
The data generated from hedonic scales is highly versatile. Computations can yield means, variance measures, and frequency distributions. This information can be analyzed by order of presentation, by user group, or by any demographic measure. The data can also be converted to ranks, which yield product preferences.
Variations of the hedonic scale exist for different purposes. A 7-point scale is sometimes used, particularly in research with children, where facial expressions replace numbers to make responses more intuitive. 5-point scales offer a simplified version for quick assessments. Research has examined how the number of categories affects consumers’ usage of the scale and its ability to discriminate between products, with the 9-point version remaining the standard for most applications.
Conducting effective affective tests
Successful affective testing requires careful planning and execution. Several factors influence the reliability and usefulness of consumer test results.
Panel size matters significantly. Research shows that companies use varying numbers of consumer test participants. During product development and optimization phases, panels of 25-75 individuals may suffice. However, before launching a product, larger consumer tests with more than 100 participants are recommended to ensure statistically reliable results. The larger sample size provides greater confidence in the data, reducing the risk of marketplace failure.
Sample presentation requires attention. Samples should be presented in random order to prevent bias. Testers should not see product packaging or branding, as external cues can influence perception. Providing palate cleansers like water or plain crackers between samples helps ensure each evaluation starts fresh.
Testing environments affect outcomes. Central location tests, conducted in controlled laboratory settings, provide standardized conditions. Home use tests, where consumers evaluate products in their natural environment over time, capture real-world usage patterns. Both approaches have merit depending on research objectives.
The role of affective tests in product development
Traditional sensory techniques, including preference and hedonic tests, remain widely used today and play a crucial role throughout the product development cycle. These methods help companies understand consumer reactions at various stages, from initial concept testing to final market validation.
During the ideation and concept stages, qualitative affective methods like focus groups help explore consumer needs and expectations. As prototypes are developed, acceptance tests gauge initial consumer reactions. During optimization, hedonic testing identifies which formulation variations consumers prefer, guiding decisions about ingredients, flavors, and textures.
Research indicates that almost 70% of food companies apply sensory evaluation methods in new product development, with most preferring consumer tests to expert analytical tests regardless of company size. This preference makes sense-while expert panels can describe product attributes, only consumers can tell you whether they actually like what they taste.
The stakes are high. Studies suggest that a significant percentage of newly developed products fail in the marketplace. Many failures stem from insufficient understanding of consumer motivation and choice. Affective testing helps bridge this gap by providing direct insight into consumer preferences before products reach store shelves.
Emerging trends in affective testing
The field of affective testing continues to evolve. Sensory scientists have been working on improving methodologies and developing new measurement systems to capture consumer responses more accurately.
Modern approaches include mobile sensory applications that allow consumers to evaluate products in real-time during regular consumption. Implicit measures using reaction time and biometric measurements capture unconscious consumer responses that traditional questionnaires might miss. Virtual reality creates immersive environments to evaluate how context affects food acceptance.
Check-all-that-apply (CATA) questions have become popular as a flexible and less time-consuming methodology compared to traditional descriptive methods. These allow consumers to select multiple attributes that describe their experience, providing richer data without the fatigue of lengthy questionnaires.
Social media mining represents another frontier, analyzing consumer comments on digital platforms to supplement traditional affective data. This passive approach captures authentic reactions without the artificial constraints of laboratory testing.
Practical considerations
When implementing affective tests, several practical factors deserve attention. Consumer sensory evaluation typically occurs toward the end of the development cycle, after analytical tests have narrowed alternatives to a manageable subset. However, earlier consumer input through qualitative methods can prevent costly late-stage discoveries.
It’s important to remember that high hedonic scores don’t guarantee commercial success. A product won’t necessarily be financially successful just because it was well liked or preferred over another product. Success in the marketplace also depends on price, market image, packaging, and positioning. However, a product that doesn’t score well in consumer acceptance testing will probably fail despite great marketing.
Consumer testing should be distinguished from market research. Sensory tests typically use coded, unbranded products to focus purely on sensory attributes. Market research more frequently uses branded products and considers purchase intent and pricing factors. Both types of research inform product decisions, but they answer different questions.
What do you think? Consider a food product you’ve recently tried for the first time. What factors influenced whether you liked it or not? If you were developing a new food product, what would you most want to know from consumer testing before launching it?
References
- https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/sensory-evaluation
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7922510/
- https://en.wikipedia.org/wiki/Hedonic_scale
- https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/hedonic-scales
- https://www.frontiersin.org/journals/food-science-and-technology/articles/10.3389/frfst.2023.1071216/full
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8001375/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8625104/
- https://link.springer.com/chapter/10.1007/978-1-4615-7843-7_13
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